Machine tool



Al-l. a. KRAUT ErAl.

MACHINE TOOL Filed Jan, 30, 1943 ll Sheets-Sheet l sept. z, 1947.v

SQPL 2, 1947. H. B. KRAUT Er Al. 2,426,621

' uAcHInE frooL y Filed Jan. 50, 1943 1l Sheets-Sheet 5 Sept. 2, 1947. H. B. KRAUT Er Al.

MACHINE TOOL Filed Jan. 30, 1943 1l Sheets-Sheet 5 fr; oww

SePL 2 1947- v H. a. KRAUT sr Al. i 2,426,621

MACHINE Toon 4Filed Jan. 30, 1943 llvSheets-Sheet 6 0 I o l a 360 o "-45 lll/l Sept' 2, 1947- H. B. KRAUT Er A1. 2,426,621

MACHINE TOOL Filed Jan. 3d, 194s 11 Sheets-Sheet '7 .WNW

MACHINE TOOL TTOQQLEQLS Sept 2, 1947- H. B. rKRUT ET Al.. 2,426,621r

MACHINE 'rooL v Fned Jan. zo, 1943 11 she'ex'sisnee'tflo f7 @www @MA/.M rromnys Sep*n 2, 1947I 1am/UT Er AL Y 2,426,621

l MACHINE T001. y 1

Filed Jan. 30, 1943 11 sheets-sheet 11 Cine 3 SGL# Patented Sept. 2, 1947 Hans B. Kraut, Keith F. `Grallimore, and Everett K.

Morgan, Fond du Lac, Wis., assignors to Giddings & Lewis Machine Tool C o., Fond du Lac, Wis., `a corporation of Wisconsin Arnilicaticm January 30, 1943, Serial No. 474,0.68

The invention relates kto machine tools and' more particularly to machines of the type commonly known'as horizontal boring, drilling and milling machines. j I

The general object ofthe invention'isto provide a large size horizontal boring, vdrilling and milling machine adapted for heavyduty usel and capable oi operating with greater precision than machines of this general character as heretofore constructed. l

More specifically stated, one objectof the invention is to provide a heavy Vduty horizontal boring,'drilling and milling machine in which the headstock and tailstock column are mounted on a translatable table orplaten for movement as a unit relative to the Work whereby extremely rigid support is provided for the tool carrying elements and the work throughout Athe machine operation.

Another object is to provide aV machine structure in which the supports for a boring bar or 20 similar tool are movable as a unit with the bar thereby avoiding the sliding of the bar 'through the tailstock or end support and providing uniform support therefore throughout the machine cycle.

Another object is mechanism for machines of the above general character adapted to materially increase their flexibility and extend their rangeof operation.

A further object is to provide'anr improved system of control for such machine tools.

Still another object is 'to provide improved safety controls effective to prevent Jamming ci relatively movable machine elements whereone elementV carries a part adjustable `in the direction l of relative movement. K

Other objects, and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated inthe accompanying drawings in which: 40

Fig. 1 is a front elevational view of a horizontal boring, drilling and milling machine embodying the features of the invention.

Fig. 2 is a plan view ofthe machine. Fig. 3 is an elevational view looking toward the 'headstock end of the machine.

Fig. 4 is a fragmentary rear elevational View of the machine. i l Fig. 5 is a fragmentary end elevational View of the machine showing a portion of the platen and 50 38 (Figs headstock traversing mechanism and associated controls.

Fig. 6 is a transverse sectional view ofthe headstock column taken in av vertical planesub- 1s claims. (omi-3) to Vprovide improved drive Fig. 8 .is a transversesectional view through the machine bed, `bridge and Work supporttaken 'in a vertical plane-substantially along the line 8-8 of Fig. 2. l

5 Fig. 9 isv a sectional 4view of the end support taken in ,a vertical plane substantially along the line B-Sof Fig. 2. i s Y Fig..10 is a vertical sectional view of the platen Ispeed and direction control mechanismtaken 10 along the line Ill-lll of Fig. 1.

, Fig. 11 is a vertical sectional view of the-work support speed and direction control `mechanism taken along the line H-II of'Fig. '7.k v Fig..12 is a diagrammatic layout` of the spindle 15 ydrive transmission and the various yfeed mechanisms of the machine. f

Fig. 13 is a wiring diagramof thefelectrical operatingV and controlcircuits of the machine.

yWhile the invention is susceptible of various modications and alternative constructions, I have shown in the drawings and will herein describe in detail thev preferred embodiment, but it is to be understood 'thatl do not intend to limit the invention to the specic form disclosed but intend tocover all'modifications and alternative constructions falling within the spirit and scope ofthe invention, asexpressed in the'appended claims. n Y Y 4General machine organization Referring now to the drawings. the machine constituting the exemplary embodiment'of the invention comprises an elongated main base or 4bed 30 (Figs. l-5) havingv horizontal guides or 35 ways 3| (Figs. 2, 6 and V8) on its upper face forY a tool supporting structure indicated generally at V32. Auxiliarybed members 33 and 34V (Figs, 1,*4 and8) extending from the vfront'and rear of the main bed respectively, approximately midway between the ends thereof, support oppositeends of a bridging member 35 (Figs. 2, 7 and 8) which extends transversely of the main bed and over the ways 3l. The bridging member, as shown in Fig. 8, comprises an elongated .bed member having integrally formed pedestals 36 and 31 45, adapted to `rest on the auxiliary bed members 33 and 34 whereby substantial clearance is provided between the ways 3| and the central sections of the bed member. The latter is provided` on its upper face with horizontal guides or ways l, 2 and 7) for a shiftable' work support 39.

. Tool supporting structure The tooll support 32 is constructed and arranged stantially along the line B--E of Fig. 2 showing 55 in a novel manner to provide extremely rigid details of the spindle driving transmission;

Fig. 7 is a fragmentary sectional view taken along the line 'l-l of'Fig; 2 showing thearrangement of the work support feed mechanism and associated controls. .Y

vibrationless support for the .tool so that the ywork may be machined with'a high vdegree of precision. Like conventional heav'yduty horizonvtal boring machines, the machine comprising the invention is provided with a spindle headstock- 4o (rigs. 1 4' and s) supported on ari upright column 4| and a tailstock or end support 42jcar ent instance, however, the headstock column 4| and the tailstock column 43 are mounted to move as a unit with a platen 45 adaptedto slide beneath the work support andthe ways 3|. The columns located at opposite sides of the Work support are thus enabled to securely hold both ends of the tool throughout fa machining operation.

The platen 45 is in the form of a flat, generally rectangular table and may beV of any preferred construction.l Slidingsupportfor the platen is provided by spaced parallel depending ways V146 (Figs. 6 vand 8) having: their lower faces machined to form bearings for engagement with the-ways 3|. Preferably these bearing surfaces extendthe full length of the platen and under both the headstock and tailstock columns so that -the cutting element .of the tool does not overhang orv extend beyond the Ypoint of supportat any time. porting structure is distributed over a relatively long surface so thatA a very rigid support is obtained. Gib plates 41 secured to flanges upstanding at the outer edges of the respective ways 3| and engaging in outwardly facingvgrooves in the sides of the Vplaten act to hold the latter securely'on the ways. To guide the platen in its movements, a ,guide'ange 48 upstanding vfrom the bed 30 adjacent one of the'ways is adapted Vto coact with avertical guide surface on adjacent rib 46 of the platen. i

` Provision is made lfor feeding the platenalong the Ways by power in either direction and at any selected one of a large number of feeding rates.

-The feed is eiected, in this instance by'means Y of a feed screw 49 adapted to be driven by a speed v Vchange mechanism 50 (Figs, 5 and 12) to be .de- Y scribed in detail hereinafter. 'Ihe feed screw .fis arranged below the platen parallel to the ways 3| and is rotatably supported at opposite ends on the main bed 30. A feed nut fixed lto the platen cooperates-with the feed screw toimpart forward or return movements to the'platen in accordance with the direction of rotation ofthe screw.` .Means is also providedA for feedingthe platen by hand foreffecting fine adjustments orthe like. Thismeans, as herein shown comprises a gear I52 (Fig. 12) mounted on thevfeed screw 49 for movement axially thereof'but held against rotation by a key or the like. 'I'he gear 52 isV rotatably anchored on theplaten and meshes with an idler gear 53 which in turn meshes with a gear 54 h'aving a bevel gear' 55 rigid therewith.` Meshing withthe gear 55'is a bevel gear 55' fast on a horizontal shaft 56 projecting at the frontrof the platen for attachment of a hand crank. Thus, by turning the crank, the screw 49 may be rotated through the gearing above `described to drive the platen in either a forward or reverse direction. 1

' The headstock column 4| is bolted or otherwise rigidly securedvon the upper face of the platen adjacent its right end as viewed in Fig. 1. The section of theplaten supporting the column is extended somewhat abovefthe upper face of the remainder of the platen to provide space for accommodating the manual traverse mechanism above described. VTo permit adjustment of the relative spacing of the headstock and tailstocks for j accommodating workpieces of Vdifferent widths,

Moreover, the weight of the tool sup-rf the platen. The means'provlded for this purpose, `as herein shown,icomprises a. dovetail slide 58 (Fig. 9) engaging in Vcomplementary dovetail grooves or ways 59 in the face of the platen.V

The headstock column, as herein shown, yis a hollow, elongated casting formed with spaced paro allel guides' or ways 60 on its front face for guiding the headstockvfin its vertical movement.V

The lower `or base portion ofthe column is ex- The headstock 40 maybeof conventional construction and as herein shown, comprisesla'casing-of generally rectangular form closedr at the front bya removable cover plate |54.V Spaced yguides 65 (Fig. 2) are fashioned yonvthe rear face ofthe casing for cooperation with thejways 60 on the column.v Removable gib plates 66 secured to the casing overlap the rearface of the: ways 60 andassist in guidingthe headstock in its nieve` ments on the Ways. Suitable' clamping Adevices (not shown) actuated in i'ivell-k'nownmanner `by Y hand levers 61 are provided. for Vclamping `the headstock in any-selectedk position on the ways. v JournaledY in the vheadstock casing with'one end' projecting laterallytherefromy isa horizontally disposed spindle 68 (Figs. Vl, 4 and12) fhaving the usual socket for the reception ofthe bor-` Y ing bar 44 or other suitable tool. The spindle is rotatably driven by the transmission 62 through a vertical drive shaft 69. and suitable gearing enclosed in the headstock casing. The driveshaft .Y shaft is journaled in a cap member V13 'rigidly' is located adjacent the side of the casingopposite the projecting end of the spindle and is arl Yranged to vproject through a, housingV 10lin`tegral with orrigidly secured to theside wall of the casing. As herein shown, the drive shaft is rotatably supported at its lower-end in suitable bearings 1| in an extension 12 at the front of the transmission housingl. The upper end ofthe secured to the top .of the column 4| and arranged to project forwardly therefrom to overhang the headstock` as shown in Fig. 3.

A driving connection between the vertical shaft as and the spind1e es is provided Vbythegearing. f

in the headstock above mentioned. As shownin Fig. 12, this gearing includes a bevel gear 14 journaled in the housinglll and having arigid sleeve 15V splined to therdrive shaft. The gear 14meshes with a. gear 16 fast on a shaft 11 rotatably supported in the headstock casing parallelwith the axis of the spindle. Provision is made for effect- Y ing a driving connection between theshaft 11 and the spindle either directly or through back gears so as to provide two diiferentspeed ranges. x To this end the shaft 11 carries a pair of gears 18 and 19; the latter of which is inconstantmesh with a gear 80 fast on a shaftil. .A pinion 82 also fast on the shaft 8| drives aV gear 83 which has a rigid pinion 84 meshing with a large or` bull gear 85 rotatably supported on the spindle. The pinion 84 and gear 85 are preferably'ofthe ydouble helical type so as to minimize end thrust on the spindle. Y

s1idab1y mounted dn the spindle 'but splined" Y thereto is a double clutch sleeve 86 having; clutch teethl 81 at one# end adapted to coact with similar clutch teeth in 'the adjacent face of thebull.

enclosed within the housing 6 I.

gear 85. Gear teeth 88 formed on the other end of the sleeve are adapted to mesh with the gear 1-8 which, as previously described, is fast on the shaft 11. Thus, by .sliding the clutch sleeve to the left (as viewed in Fig. 12) a driving connection is established between the bull gear and the spindle so that the latter is rotated in the. low speed range through the medium of the back gears 19-85. Shifting of the clutch sleeve to the right to mesh the gears 18 and establishes a direct driving connection between the shaft 11 and the spindle whereby the spindle is driven in the high speed range. The clutch sleeve may also be set in the intermediate or neutral position in which it is shown in the drawing so as to interrupt the spindle drive. Any suitable means, such as a hand lever 89 (Figs. 1, 3 ahd 4) may be utilized for shifting the clutch sleeve.

The transmission '62 by which the vertical shaft 69 is driven may be of any suitable type. The

particular machine illustrated is provided with a' transmission of the nine-speed typeV similar to that disclosed in the Schurger Patent No. 2,269,- 290, granted January 6, 1942. Briefly described,

this transmission comprises an inlet shaft 90 (Figs. and 12) an intermediate shaft 9| Vand an outlet shaft 92 with suitable clutches an'dgearing for interconnecting these shafts in nine differf ent speed transmitting ranges.` The-shafts are all rotatably supported in a suitableframe' 6| Referring more particularly to Figs. 6 and 12 of the drawings, the outlet shaftv92 of the transe mission is connected with the shaft 69 byi-bevel gears 93 and 94. The inlet shaftA 90 is driven by a reversible electrical motor M herein shown as flange mounted on the rear wall of the headstock column 4| with its shaft 95 projecting into the transmission housing. A coupling 96 connects" the motor shaft with a driving shaft 91 journaled in the frame 6|v and having a pinion 98 mesh-Q ing with a gear 99 keyed tothe inlet shaft 90. Loosely journaled on the inlet shaft 90 are a vpair of end gears and |0| adapted to bevalternatively coupled to the shaft by a centrally disposed clutch member in the form of a sleeve |02 splined tothe shaft. Rigid with the clutch sleeve is a vgear v|04 adapted when the clutch is Y in=a central A-position and disengaged from both of the end gears, to mesh with a gear |05 fast on the intermediateV shaft 9|. Gears |08 and |01 also fast on the shaft 9| are in constant mesh with the end gears |00 and |0| respectively. Thus by appropriately shifting the clutch sleeve .|02 any one of three driving connections each with a different gear ratio may be established selectively between the inlet shaft 90 and the intermediate shaft 9|.

A similar 'clutch and gear arrangement provides three selectively yengageable driving connections lbetween theV intermediate shaft 9| and the outlet shaft 92. Thus, gear |08 and |09 loosely journaled on the shaft 92 mesh with pinions I0 and respectively fast on the shaft 9|. A central clutchmember or sleeve ||2 splined on the shaft 92 is shiftable to couple either gear |08 or |09 to the shaft. Moreover, the clutch sleeve has an integral gear ||3 engageable withithe gear |05 when the sleeve is located in its central or neutral position.

Since the clutch members areshiftable independently and since each provides connections of thr'ee different gearratios between their respective shafts and the intermediate shaft, it` will be apparent that the 'outlet Vshaft may be 6 driven from the inlet shaft at any one of nine progressively different speeds. It will be recalled that the gearing in the headstock includes additional means for selecting between a high and low-speed range, thus doubling the range of theV transmission 02 or, in other words, providing eighteen progressively different speeds for the spindle 68. It will be understood that additional speed changes may be obtained', if desired, by varying the speed of the driving motor M.

Any suitable means may be utilized for shifting'therclutch members |02 and ||2. Shifting mechanismofthe type Adisclosed in the Schurger patent above referred to-is preferred sinceV the different driving ratios may be established progressively by simply turning a hand crank ||4 (Figs. 1, 2, 3 and 5) projecting at the frontv of the transmission housing. The particular driving ratio in effect at any time is visually indicated by a suitable indicator associated with Vthe shifting mechanismV and arranged to display appropriate indicia through two openings or windows ||5 and ||6 in the front wall of the housing. The indicator is ordinarily calibrated so thatthe indicia displayed through the window |.|5 shows the. speed at which the spindle is driven in thelow speed range, that is, when the back gears of the headstockare engaged.- The indicia displayed in the window |16 shows the spindle speed in the high speed range or when the drive is taken directly from the shaft 11.

Provision is made for feeding theheadstock 40 vertically-either by power or manually, as de- `sired`. The feed mechanism as herein shown,rin

cludesY a Vertical feedscrew H9 (Figs. 1, 6 and 12),.threaded into anut |20 carried on the headstock casing. The feed screw extends into the cap member 13 and is rotatablyanchored therein in any suitable manner. At its lower end the feed screw is journaledin bearings |2| (Fig. 6) carried on the platen 45 and is arranged to be drivingly connected with a splined shaft |22 extending longitudinally `of the machine bed vbelow the platen. The connection is provided in this instance by a bevel gear |23 fixed on theend of K the feed screw and meshing with a bevel gear |24 splined on the shaft. The latter gear is rotatably anchored in a casing |25 rigid with the platen so that the gear travels along `with the platen in its movements on the ways and isoperative to transmit power to the feed screw in any position of the platen.

The shaft |22 is journaled at opposite ends in suitable bearings |26 (Fig. 5) carried on the machine bed 30 at opposite ends ofthe ways. Power is applied to the shaft at the head end-[of the bed through the medium fof the feed mechanism 50 (Figs. V5 and 12) which is adapted to be coupled selectively to the shaft or to the platen feed screw 49 as will appear presently.

Means istalso provided for manually rotating the shaft |22 to facilitate accurate positioning of the headstock when initiallyr setting up the machine. The manual operable means, as shown in Fig. 12, includes'a gear.|29 rigid with the bevel gear |24 and meshing with anidler gear |30 ro'- tatably mounted in a suitable compartment in .the platen 45.. The gear |30, in turn, meshes .with a gear |3| rigid with a bevel gear |32 meshingwith a bevel gear |33. Thelatter gear is Akeyed'to a shaft |34 arranged to project at the 1 crank by which the shaft may be turned.l A

guard |36 (Figs. V1, 3 and 5), openv atthe outer f platen.

The mechanism above described for traversing the'headstock is also utilized for traversing'the tailstock 42 insynchronism therewith.Y Vertical 'movements are imparted to the tailstock' through the medium ofk a feed screw |38 coacting withav stationary nut |39 (Fig. 12) carried on the tail-YV stock. The latter as hereinl shown,y comprisesia ygenerally rectangular block 14g Fir-gs. 1 andz) havipg al.ffiflfdly projecting braeket |41 homing a sleeveor bushing |42 Yfor rotatably supportingthe outer end'of the toolbar 44. Parallelv spaced guidewayns are fashioned on the rear face of the block |40 for cooperation with vertically disposed guides or ways |43 on thev front vface of the' tailstock column 43. VRemovable gib plates |44 secured to the block are arranged to voverlap the rearface of the' ways |43 to assist in guiding the tailstock in its movements. Suitable clamps .operated by hand levers |45V are provided for locking the tailstock in any adjusted position.

y'I'hetailstock column 43 is preferably in thev form of aA hollow! elongated casting of generally rectangular horizontal cross section. The ways |43 are formed on the front face ofpthi's column and the feed screw is arranged to extendupward- 'lybetween the ways.

screw isrotatably anchored'in a cap member |46 @bolted or otherwise rigidlyY secured tothe top of the column.` The lower end of the column is preferab'lyv formed as a separate generally rectangular base |41 to which the column portion may be fv'bolted or otherwise rigidly secured. key |48 `.(Fg. 9) projecting from the upper face of the Y "base engages in a keyway in the bottom 'of the column portion to accurately Alocate the latter At its upperend the feed withrespect to the base.

As shown in Fig. 9, the'feed screw |38 is'rotat-4 ably supported vat its lower end ina bearing |49 carried `on the column'base |41'an'd has a bevel l Ygear |50 keyed thereto for engagement with a bevel gear splined' on the shaft |22. Thev latter gear isY rotatably anchored in' a housing |52 secured to the underside of the column base and projecting through a longitudinal slot '|53 in the rplaten 45. This slot provides clearancefor the feed screw and associated mechanisms in various adjusted positions of the tailstock `column Yon the yAs :previously slide V58Y engaging in the dovetail grooves or ways 'able means may be utiuzed for shifting the tait Ystockcolumn along lits ways.` AsV herein shown,Y

the adjusting means is enclosed withinfa' chamthereto. Thus byY simply theY tailstock may be shifted either toward-vor from the headstock` column, as desired. Conventional clamping means including a clamping screw-|60 arranged to be vactuated' by a hand lever |6|v (Figs.

land v9) is operative to lock the tails'tock column 5 4in any set position. f

'Platen and neadst'oek fee-dfi'.

Reference been made heretofore to the feed mechanism 50 and its'adaptability'for traversing the headsteck '4o and tailstoekraz vertically von their respective columns and fortranslating the platen 45 horizontally on the ways 3|,'The

Ause of a single feed mechanismfor ,thispurpose materially simplifies the machine vstruotureand provides an exceedingly wide range of feed speeds I for a1l of themovable machine elements without complicating ythe controls therefor. 1n general the feed mechanism is arrangedto drive either'the headstock` and ,tailstock or the platen'jatafselectively variable ratein' either a high speed range or a low speed range. Additional sp'e'ed`ranges may be obtained if desired by providing approeration.' Y x f i Y As shown inFigs. 4 and 1 2 the feed mechanism priate speed `change gearing or equivalent Vspeed Ycontrol devices' of conventional form. Thespeed y ranges are selected manually at the beginning of [an kvoperation or at any` other suitable time, and ordinarily remain unchanged until the operation is completed. WithinL this range however,A means is provided whereby the feed'ratemay be varied inV incremental steps while the machine is in opinits preferred form comprises a variable speed reversible hydraulic transmission unit |62 of any well-known type having va power inlet or driven.

' shaft |63 andan outlet or driving shaft |64;Y The stated, the tailstockscolumn is adjustably secured to the platen by the dovetail' inlet shaft is directly connected with th'e'shaft lof anfelectric motorjMf as by acoupling |63' and Y vis'driven continuously thereby at a uniform speed;V

Themotor and the hydraulic'unit may be conveniently mounted on the-.back Wall of the Amain bed 30 as shown in Fig. 4` and are conveniently enclosed in a ventilated housing |v (Figs. 2', 3. Y

and 5). y v

Both thespeed and thedirectionof rotation of the outlet shaft |64 are adaptedto be controlled 50 in well-known manner. In the 'particular transmission unit shown herein'the direction lofgrotation ofthe outlet shaft is controlled by arpair of seieneid's son-l and son-2 F1gs.4 and 13) f 'Y `acting ythrough suitable valves Vor the lke (not f shown). vIn this instance the arrangement is ber formed in the base |41 and' includes a ver- "tical shaft |54 having its lowerV end projecting below the slide 58.Y '1A pinion |55 xed on themejecting end of the shaft meshes' with a rack |56 extending along `one side edge of the slot |53 and l rigidly secured to the platen.

Ythe inner end of a horizontal shaft |59.. The shaft is rotatablysupported in the base with its outer end projecting at' the front ofthe machine. A

socket |59 in the projecting shaft end provides vmeans for operatively connecting a hand crank such that the outlet shaftis driven rin onedirection, for example clockwise when theysolenoid SOL--I is energized and inv the reverse direction or counter-clockwise when both solenoids are energized. The speed `of rotation -of Ythe outlet shaftris regulated by a shiftable plunger |66 opt eratingthrough appropriate control mechanism Y.

enclosed in a casing- |61 forming a part of lthe transmission unit.

' Provision is made for selectively connecting the y outletshaft` |64 of the' transmission` unitwith either the platen feed screw 49-or with the drive shaft |22 andfifor either high speed or lowspeed operation. vThe. means for effecting thespeed 'range selection includes twoispeed gearing and able typeTdrivinglyrco'nnects the outlet shaftk lclutch devices enclosed inal housing |68 set in a.

recess in 'the head YendV of the main-'bed 30 as` shown in Figs. 2-5. A coupler-`|69 cf any suit- |64 witha shaft |10 journaled inthe housing |68 and having` on its inner endan elongated pinion turning the shaft |59" Y l a42ae21 |1| (Figs. 5 and 12). A'cluster gear |12 arranged to slide longitudinally ofthe pinion |1| has a large gear element |13'in constant mesh with element |13 when the cluster gear is shiftedto f the high speed position. Both gear elements of the cluster gear are disengaged and the drive interrupted when the cluster gear is set in central or neutral position in which it is shown in Fig. 12.

The means for shifting the cluster `gear tol select either driving range Aincludes a shoe |80 (Fig. 5) ,slidably supported 'for movement axially of the cluster gear by spaced parallel guide bars |8| carried in the housing |68. A rigid arm |82 extending upwardly andrearwardly from the shoe is formed with a yoke adapted to receive the periphery of the gear element |14 and operative to carry the cluster gear along with the shoe in the movements of the latter on the vguide bars.

Fashioned on the forward edge rof the shoe |80 is an upwardly facing rack |83 engaged by a segmental pinion |84 keyed to a horizontal shaft |85. The shaft is journaled in suitable brackets |86 rigid with the bottom wall of the housing |68 and is arranged to extend transversely of the machine bed. Forrocking the shaft |85 to selectively position the shoe' |80 there is provided a hand lever |81 accessible at the front of the machine (as shown i'nFigs. 1, 3 and 5) The hand lever is flXed on the projecting end of a shaft |88 extending through the frontv wall of the bed 30 and the adjacent lwall 'of thegear housing |68 suitably journaled therein. y A pinion |89 keyed to the shaft within the gear housing meshes with a gear |90 keyed to the shaft' .|85 and provides a 'driving connection between the two shafts. The

gear ratios are preferably such that the high speed range may be selected by rocking the lever |81 from an upright position through a relatively small angle to the left (as viewed in Fig. 1) while the low speed range may be selected by rocking' the lever to the right through a similar angle. With the lever in `upright orvertical position, the cluster gear is set in neutral position thus interrupting the drive.

Referring again to Figs. 5 and 12 the idler gear |18 is arranged to drive a'gear |9| rigid with an elongated `pinion, |92. Any axially slidable clutch gear |93 in constant mesh with thispinion is adapted to be shifted into meshing engagement selectively with a gear |94 fast on the end of the platen feed 'screw 49 or with argear |95 `fast on the headstock and tailstock traversing shaft |22. The clutch gear may also be set in a central or neutral position in which the drive is disengaged from both the screw andthe shaft.

Any suitable means may be utilized for shifting the clutch gear |93 to establish the driving connections above referred to. As' shown in Fig. 5, this means comprises a shoe |96 slidably'supported on spaced parallel guide bars |91 and having a rigid arm |98 formed with a pocket adapted to receive the periphery of the gear |93. The shoe |96 is shifted along the guide bars by means of a hand lever |99 accessible at the front of vthe f |58. A pinion on the inner end of the shaft 20|) is arranged to engage a'rack 202 on the rear edge of the shoe |96 to transmit the movements of the'hand lever to the shoe.

With the arrangement above described the gear |93 may beengaged with they gear |94 to drive the feed screw 49and thusV feed the platen on its ways by rocking thehand lever |99 through a relatively small angle to the left ofthe upright position in which it is shown in Fig. 1. Alternatively, by rocking the lever to the right the gearv |93 is engaged with the gear |95 so as to drive the shaft |22 and thus traverse the headstock and tailstock on their respective columns as previously described. The yspeed atV which these -movements are effected is determined by the setting of the speed range selector gears `and f by the adjustment of the hydraulic transmission machine and preferably disposed closely adjacent f the speed selecting lever |81. This hand lever unit |62. The direction of vmovementis determined by the setting'of the'hydraulic'transmissionunit for ,forward or reverse rotation of the outlet shaft.

Speed and direction control n The direction of movement of the movable elements of the work support including the headstock 40, tailstock 42 and l platen 45 and the rate of'such movements within either of two selected speed ranges is determined by the adjustment of the hydraulic variable speed transmission unit tively large size, such as the vexemplary machine,

duplicate control levers are provided at two or more-stations,A so that the attendant may con-` trol the machine with the greatest convenience. Referring now to Figs. 1, 4 and 10 ofthe drawings, the speed and direction control mechanism, as hereinshown, comprises a pair of control units 2|0 and 2|0' mounted on thevfront wall of the machine bed 30 at conveniently located'stations preferably on opposite sides of the work support 39. It will be understood of course, that the two unit arrangement shown` ls -merely illustrative and that one ,orin fact any number of such units maybe provided according tothe particular requirements of the machinevinvolved.` As these control units .are of the same construction a description of one will sumce. n n

The control unit 2 I0, as shown in Fig. 10, comprises a generally cylindrical housing 2|| `having an eccentrically located, rearwardly extending hub portion 2|2 rotatably supportediin` a panel.

2|3 adapted to'bebolted or otherwise removably secured over a flanged opening2|4 in thefront Wall of the bed 30; 'Ihe body of the housing 2|| engages the frontfwall of the paneland a gear element 2|5 securedtol the inner end of the yl'iub 2|2 as by a'setscrew 2|6 engages the rear Wall' of the panel to hold the housing against axial movement while permitting it to rotate freely in the panel.

Extending through the housing 2|| and the hub portion 2|2 is an axial bore 2|1 connecting with a transverse bore 2|8 in` the body of the housing. 'A cylindrical plunger 2|9 is slidably supported inthe first mentioned bore and is held forthe action of the tool. vIt will-.be appreciated,

however, that'the transverse movement of the support maybe employed in'fee'dirig4 the work .relative to the tool 'in certainoperationssuch as" milling. The "invention" ffurtl'i'ery provides means by which thesupportedworkpiece Amaybe rotated about a vertical axis. .'I'herotative movements are likewise utilizedin positio'ningsthe `work Aalthough if desired, such v'movement'may be emthe ways 3.8 on the bridging membery35. Horizontal'gib plates` 252 secured tothe bridging member and engaging in rgroovesfon opposite sides of the slideract to hold the same securely on the ways. A vertical gib plate 253 may be provided between one of the yguide flanges 275| and `an adjacent shoulder- 'presented by an vupsta'aiding flange ,254 vonthe bridging `member tro ltake up any'lateral playbetween the slide and the ways. f

Provision is made for traversing theslide on 125 the ways at selectivelyovariable speedsin'either direction. The traverse movements are imparted to theslide, inthis instance `by afeed lscrew 25,5

(Figs. 2, .'l and 12) fcoacting with a fixed nut 256 30 on the slide. Thelfeed screw' is arranged horizontally in a vcompartment formed in thebridging member below rthe ways,38 and isv rotatably anchored at one y,end in a bearing A261 on the rear wall of the. bridging member. The otherend of the feed lscrewfe'xtends linto agear housing 258 (Figs. 'land 8) `rigidly mounted at the4 front of the bridging ,member and enclosing driving mechanism to be described hereinafterfor rotating the feed screw. A suitable bearing supports the forward end of the feed screw on the rear wall of the housing 258.v

While the work to be operated on may be supported directly on the 'slide 250, it is preferred to provide an auxiliary table 260 for this purpose. In the exemplary machine the tableis ysupported on the slide for rotation-by a vertical axisalthough other types of `rnountings may be femployed if desired. The table 266, as herein shown, comprises a fiat generally rectangular top section having longitudinally Iextending stiffening ri-bs 26| on its underside and Tslots.,262,i n-its upper face for reception of conventionalv work clamping devices. Integral with or rigidly secured to the top section is a base section'263 `also of generally rectangular form but of slightly greater dimensions than thetop section. An lupstanding flange `264 `around the periphery of Vthe bottom section 263 and spaced from the edge of the top section defines a'trough around thetopzcf' the table. I

As shown in Fig. 8, the table structure `is mounted on a vertically disposed spindle v-265 anchored in an upstanding boss 266 substantially at the center of the slide 250. The base section 263 of the tableis formed with a circular opening concentric with the spindle while the top rsection has a depending hub` 261 axially alined koo with this opening. The hub is formed with a cylindrical bore dimensioned to receive the `upper end of the spindle and with a counterbore adapted to seatfthrust bearings 268 for cooperation with, the spindle. The counterbore may be closed at the top by a plug 263 having its upper surface flush with the face `of the table.

14 ,'Ine .table Structure 1S Supporte@ ,at its periphery-by Moller bearing of 'large ,dimeter'tolredue friction and thus permit easyfmovement vthe table.` The bearing, as herein shown, compris fes 'a hardend weer ,ring 210 .Suitablyehehard t0 the slide 2,50 r`and Iforming a track for a :series of balls v21|. `A similar wear ring 212 attached ,to tne'urrdersme yof thetjabie base `:te 1s 'adapted .to rest on the balls21l`vand thus V'support the rllvfeigl'lt of the table'. i

' Means is provided for clamping thetabie in Aany vselected angular position whenthe workis to be held stationary during a machining operation. For this purpose the upper face of the 'slide 256 and vthe adjacent faces of vthe table base y'263 are formed `with axially alinedy annularf'ariges ,213 and214 encircling wear'rings ;21 0 andf212 respectively. .The flanges project intol closely abutting ,relation and are oppositely beveledI on their outer surface for engagement in a V-'shaped groove formedin ythe inner 'faceof an annular clamping member 215.

The clamping member is preferably constructed in ltwoparts or semi-circular sections pivotally connected together at the rear ofthe slide and anchored thereto as by a pin 216. The opposite yendsof the sections are adjustably .connected 'by a clamping screw 211 rotatably "anchored in a boss 218 on one section and threaded intoa similar boss 219 on the other section. The sec,-

tion ofthe screw exposed between the two bosses is protected from chips or other foreignvmaterial bya shield 2800i sheet metal or othersultable material.

The outer end of the clamping screw is `extended to` the side of thetable wall'fordconvenient access and the'end portionI may be squared 1 or otherwise formed for engagement by a wrench or similar tool. By turning the screw, the sections of the clamping ring may be drawn together into tight engagement with the beveled surfaces of the flange 213 and 214 so as to prevent rotation of the table. Moreover, the lclampingring exerts a wedging action on the flanges tending to force their adjacent surfaces intofrictional engagement and thus reenforce the rstfrrietioned clamping action. In this wayka very powerful yclamping effect is obtained vwhich precludes any movement of the table during a machining operation. When thetalble is to be rotated, the clamping Aring is released by turningth'e clamping"j screw in a direction to' separate the ring sections.

Rotation of the table 2-60fr`naybe efiedtedinany suitable manner. In the particular fylniachineil- 1ustrated the means provided for :th sip comprises an internal,ring*` l o y 12) bolted or otherwise rigidly secured toffihf table base-263.11.13@ the brlig im@ .3.1.2 and concentric with the spindle 265i 5M' hi with thegear 282 is a pinion283 fast ont of a vertical shaft 2,84 rotatably supported on he yslide r250'. A worm wheel 23,5 fastlontheflowyer end ofl the shaft is arranged to be driven ,a worm 286 splined to a horizontal driveshaftl281 extending longitudinally `cf the bridging rxnerxibver 35 below the ways .36. 'Ifhe` rWorm *wheel28f5 yrid worm 286 are Arotatably supported inwahou ng `288 `secured to the undersideofthe table sli 6 so that the wor-mis freeto slide along the shaft' and maintain the driving connection A' v the tablein all positionsjof the slide'.

15 ingV 258 and is supported on the rear wall of the vhousing by a suitable bearing 290.v Driving mechanism within the housing is adapted to be .con; nected to the shaft 281 or alternatively with the feed screw 255 as will now be described.

`. Table' drive mechanism is substantially reduced without sacrifice of emciency or flexibility as the independent feed mechanisms provide a complete range of feed and rapid traverse speeds for eachv of the machine elements.

1 Referring more particularlyy to Figs. 7, 8 and 12 of the drawings, the work support driving mechanism in its preferred form includes a reversible variable speed hydraulic transmission unit 300` of any suitable and well-knownV type preferably similar to the transmission unit |62.- The transmission unit 300 may be mounted on a suitable base 30| secured to the'auxiliary bed member 33 at the front-of the main bed. The unit has the usual inlet or driven shaft 302 adapted to be driven continuously at a uniform speed, and an outlet or driving shaft 303 adaptedto turn at any selected rate'within the capacity of the unit.

In the particular unit shown the rotational speed of the outlet shaft is ,regulated by control mech-l anism of well-known construction actuated by means of a plunger 304 (Fig. 8). Solenoids SOL- 3 and SOL- 4 control the direction of rotation of the outlet shaft in well-known manner.

lThus, when the solenoid SOL-3 is energized, thev shaft is rotated in one direction while energization of both solenoids causes the outlet shaft to? be rotated in the reverse direction.

As herein shown, the transmission unit 300 is arranged to'be driven by the motor M which, as`

previously described, 'also drives the transmission unit |62.

by a coupling member 306. `'I'he shaft/extends The driving connection between the 1 Vmotor and the unit includes a' shaft 305 (Figs. 4 l and 12) coupled at one end tothe motor shaft from neutral position in which it is shown in Fig. 8 into alternate position effective to drive either the feed screw 255r or the shaft/281. When shifted to the right (as viewed in Fig. 8), the

clutch gearpmeshes with a gear 32| fast ontl'ie.`

table drive shaft 281 thus renderingthe transmission unit effective to drive the rotary vwork table 2&0. When shifted to the alternate position, that is to theleft (as viewed in Fig. 8) the clutch gear engages a gear 322 fast on the feed screw 255 andthe transmission unit isthereby coupled to the table slide feed screw 255. In the A y central or neutralpositionof the clutch gear,

the drive is disengaged from both the shaft and thefeedscrew.y v' Y vf For shifting the clutch gear 3|9 there is pro- 'vided a shifter fork 323(-Fig. 7) slidably supported at one side of the shaft 320 on the parallel spaced guide rods324 carried in the housing 258. The shifter fork isformed with a laterally. projecting shoe 325 having a pocket or groove d1- mensioned to receive the peripheral edge of the clutch lgear and operativev to slide the gear along its shaft in response to corresponding movements of the fork.- l

While any suitable means may be utilized for shifting the fork between the three ,positions above ymentioned, they exemplary 'machine is equipped with a hand lever 326 forthis purpose.

is shown in Fig. 7, the` hand lever is fixed on the projecting end of a horizontal shaft 3ljournaled ina bushing 328 carried on theside wall Aoi the auxiliary bed member` 34.l The-shaft extends into the gearhousing 258 and has on its inner end a pinion 329 meshing with an yupwardly fac- 1 ingrack formed along` one side of theshifter longitudinally of the main bed 30 and into the rear bed member 34 in which it is rotatably sup-` ported in a bearing carried by a housing 301 re-` movably secured to the rear Wall of the bed mem-` ber as shown in Fig. 8. A cross shaft 308 extends forwardly from the housing to the transmission` unit and is drivingly connected with the inlet shaft 302 by a coupling member 309. the housing 301, the bevel gears 3|0 and 3| keyed respectivelyto the shafts 305 and 308 drivinglyl connect the same.

Suitable mechanism is provided within thegear housing 258 for selectively connecting the .outletj rshaft 303 of the transmission unit with either the table slide feed screw 255 or the table drive shaft` 281. To' this end'the outlet shaft is connected by a coupling 3|2 with a shaft 3|3 journaled in V l the housing 253. A pinion 3|4 fast on the shaft 3|3 is arranged to drive a gear 3|5 through an idler gear BIE. The gear 3|5 is keyed to a shaft' 3|l which has a rigid elongated pinion 318. A`

clutch gear 3|9 splined on a shaft`320 for sliding movement parallel to the pinion shaft is continuously in mesh with the pinion. g The clutch gear 3|9 is adapted to be Within y shifted fork. The pinion is dimensioned so that the vfori; may be shifted to either of the two driving positions by rocking 4the hand lever through a'relatively small angle at either side of the vertical or neutral position. Y y

In addition to the power drive` means'for traversing the slide 2'50 and for rotating the table 260, manually operablemeans is usuallyprovided for moving these elements to facilitate initial setup of the machine for operation. The manually operable means, as herein shown, .comprises a shaft 330 (Figs. 3 and) projecting from opposite sides of the auxiliary bed 34and` provided on its outer ends with suitable clutch teeth or the like for engagement with ahand crank. The shafta 330 extendsthrough thelgear housing 258 and is provided intermediate itsends with a pinion 33| meshing witha crown gear 332 keyed to the shaft 320 on whichr the clutch gear 3|3 is mounted. Thus the shaftfand .clutch gearvmay f .be rotated manually when desired andthe gear,

of course, may be lengaged selectively to drive either the feed screw 255 or the shaft'28l as bei fore explained. Tubular guards 333 and 333' (Figs. 1 and '3) are provided for projecting ends of the shaft 330 to prevent accidental contact therewith when the power drive is engaged. The guards. are open aty their outer ends to admit the hand cranks when used. t

Table Speed land direction controll l -Control mechanism ,is provided Whereby'the 'f attendant may regulate the speedr and controlA the direction of movement of the slide 250 or the table 260.by means of a single vhand lever 335,. This mechanism is similar in general to the platen drive control mechanism hereinbefore described and, as in the previous instance, is duplicated at two different stations for the conven- 17 ience of the attendant. As herein show the stations are located on opposite sides of the work support and corresponding parts are designated by the same referencecharacter with those of the auxiliary or duplicate control being further identied by a prime number.

Referring to Figs. 7 and 11, a hand lever 335 is pivoted intermediate its ends in a rockable housing 336 journaled in a. panel 331 removably mounted on the side wall of the bed member 34. By swinging the hand lever in a plane substan- .tially parallel to the path of the table slide, rocking movements are imparted to the housing which acts through a gear segment 338 to shift a cam bar 339. The bar is formed with cam surfaces positioned for cooperationr with a pair of control switches FS-l and RS-l, the arrangement being such that the switch FS-I alone is closed upon movement'of the cam bar to the left (as viewed in Fig. 11) while both switches are closed upon movement of the bar to the right.

Closure of the switch FS-I completes a circuit for energizing the'solenoid SOD-3 to condi- I,

As shown in Fig. 8 a pinion 353 keyed to the shaft 348 within -a housing formed in one of the brackets`350 meshes with rack teeth 354 formed in the projecting end of the speed regulating plunger 3704 vof. the transmissionunit 300.

Also cooperating with `the pinion 353 is a rack 355 urged by a spring 356 in a direction toshift the plunger 304 toward the stopping position.

The action of the spring 356 is transmittedv positionby means of a rotatable knob351 (Figs. -1 and 3), acting. through mechanism` similar in all respects to thatshown in Fig. 10. The setting of the stop does not prevent shifting of the control lever to rapid traverse position but determines .the feed rate to which the drive mechanism will automatically return whenk the hand lever is released. l

` Limit controls lSafety stop means is provided in connection with the various linearly translatable machine remains stationary.

To facilitate control of the machine operation,v

the duplicate control device previously referred to is provided on the opposite side of the work support. This control device is similar in all respects to the companion control device `except that the cam bar and associated controlswitches are omitted. Instead, provision is made for transmitting the movement of the housing 336 to the housing 336 whereby the cam bar and control switches may be actuated under control of either hand lever 335er 335'. To this end a shaft 340 extending across the bed 34 is provided at one end with a pinion 34| meshing with the gear teeth 338 on the hub portion vof the housing 326, the gear teethbeing extended rearwardly for this purpose. At its other end the shaft is provided with a pinion 34| meshing with gear teeth 338' formed on the hub portion of the housing 336. To facilitate removal and adjustment. of the control apparatus, the shaft 340 is conveniently formed in two sections operatively connected by a splined coupling 34,3,

As in the case of the platen controls, thetable control hand levers 335 and 335' are also utilized for regulating the feed rate of the table slid Aor table. For this purpose the hand levers are arranged respectively to shift plungers 344 and 344' axially within the housings 336 and 336'. These provided respectively with bevel gears 35| and 35| meshing with bevel gears 352 and 352' keyed to opposite ends of the cross shaft.

elements to arrest the power drive when the elements have reached the limits of their travel in either direction.` This means comprises suitable limit switches and, in the case of the headstock 40* and table slide 250, simple switch actuators secured t'o and .movable with the respective elements. Thus the headstock is provided with an actuator in the form of a, cam plate or dog 360 (Figs, 3 and 6) adapted yto coact alternately. with an upper limit switch I S--l and a lower limit switch LS-2. These switches are incorporated in the control circuit as shown in Fig. 13 so as to interrupt the drive for the headstock when either the upper or the lower limit of travel is reached.

A similar limit control arrangement is provided `LS4 respectively. The dog 36| is secured to the underside of the table adjacent its rear end and `is positioned to coact `with the switch LS-3 which is stationarily supported on a bracket 363 carried on the bridging member which supports the slide. The dog 362 is mounted at the front end of the slide to coact ywith the limit switch LS-4 which is suitably supported on the front portion of the 'bridging member. Thesewlimit switchesare incorporated in the control circuit as shown in Fig. 13 and described hereinafter.

4 Thearrangement of the limit switches for the platen presents a more difficult problem because of the adjustable mounting of the tailstock column thereon. Thus, in order to prevent the tailstock column from being jammed against the work support, the travel of the platen must be confined within limits which vary according tothe po-l sition of the column on ythe platen.

To insure safe operation under all working conn l ditions, one switch actuator or dog 365 (Fig. 9) is rigidly attached directlyr to the platen while a second switch actuator or dog 366 is secured to the column base |41 for movementtherewith relative to the platen. The fixed actuator 365 is arranged to cooperate with a limit switch LS-5 toiinterrupt the feed of the platen as the latter 

